Main Entry: mas·to·don Pronunciation: 'mas-t&-"dän, -d&nFunction: nounEtymology: New Latin mastodont-, mastodon, from Greek mastos + odont-, odOn, odous tooth -- more at TOOTH1 : any of numerous extinct mammals (genus Mastodon syn. Mammut) that differ from the related mammoths and existing elephants chiefly in the form of the molar teeth2 : one that is unusually large

Knowing that mastos in Greek means breast and odontos means tooth, does that mean that the mastodon is an animal with a tooth on its breast?

mastodon 1813, from Mod.L. genus name Mastodon (1806), coined by Georges Cuvier from Gk. mastos "breast" + odont- "tooth," so called from the nipple-like projections on the crowns of the extinct mammal's fossil molars.

In 1953, an electrician working in the basement of a building in Philadelphia, Pennsylvania, unearthed a grey and white stone about the size of a large grapefruit. The basement was in a building that had belonged to one of the architects of American independence: Benjamin Franklin. The object was a fossilized mastodon tooth.